At the beginning of the school year, the authors, a first-grade teacher and a teacher educator, worked together to "spice up" the first-grade science curriculum. The teacher had taught the unit Rocks, Sand, and Soil several times, conducting hands-on explorations and using books to help students learn about properties of rocks, but she felt the books' "big" words--igneous, sedimentary, metamorphic--often held little meaning for first-grade students. In reworking the unit, the authors first established a framework to guide their curriculum planning. They decided to keep much of what had been taught in previous years but to expand it to include new lessons to which students could physically connect and a culminating experience--Rock Day--that would synthesize the unit's content and help assess what students learned in a creative and memorable way.